Effect of Heat Treatment Temperature on the Color of Okan Wood

2011 ◽  
Vol 214 ◽  
pp. 531-534 ◽  
Author(s):  
Qiang Shi ◽  
Fu Cheng Bao ◽  
Jian Xiong Lu ◽  
Jing Hui Jiang
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Color Change ◽  
Treated Wood ◽  
Color Difference ◽  
Treatment Temperature ◽  
Strong Correlations ◽  
Color Changes ◽  
Color System ◽  
Effect Of Treatment

In this study the effect of high temperature on color change of okan wood was investigated. Wood specimens were subjected to heat treatment at 160°C, 180°C,200°C,220°Cfor 4 hours with the superheated steam as a heating medium and a shielding gas. Color changes were measured in the Minolta Croma-Meter CR-300 color system. The color parameters L*, a*, b* were determined by the CIEL*a*b* method on the surface of untreated and treated wood, and their variation with regard to the treatment (△L*,△a*,△b* ) were calculated. It was found that heat treatment resulted in a darkening of wood tissues, Color became dark with the temperature increases. The darkening accelerated when treatment temperature exceeded approximately 200°C. We found that heat treatment temperature were substantially important regarding the color responses. Strong correlations between total color difference and the treatment temperature were found. The effect of treatment temperature on color change in sapwood is more obvious than that in heartwood, the color of sapwood and heartwood tended to be more uniform when the temperature reaches more than 200°C.

Comparison of the color and weight change in Paulownia tomentosa and Pinus koraiensis wood heat-treated in hot oil and hot air

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5574-5585
Author(s):  
Intan Fajar Suri ◽  
Jong Ho Kim ◽  
Byantara Darsan Purusatama ◽  
Go Un Yang ◽  
Denni Prasetia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Color Change ◽  
Treated Wood ◽  
Pinus Koraiensis ◽  
Weight Changes ◽  
Paulownia Tomentosa ◽  
Wood Color ◽  
Color Changes ◽  
Hot Air ◽  
Heat Treated

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

Effects of Heat Treatment on some Physical Properties of Douglas Fir (Pseudotsuga Menziesii) Wood

2011 ◽  
Vol 197-198 ◽  
pp. 90-95 ◽  
Author(s):  
Xian Jun Li ◽  
Zhi Yong Cai ◽  
Qun Ying Mou ◽  
Yi Qiang Wu ◽  
Yuan Liu
Keyword(s):  
Heat Treatment ◽  
Physical Properties ◽  
Pseudotsuga Menziesii ◽  
Treatment Time ◽  
Treated Wood ◽  
Untreated Wood ◽  
Douglas Fir ◽  
Treatment Temperature ◽  
Color Changes ◽  
Moisture Performance

In this study the effect of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) was investigated. Wood specimens were subjected to heat treatment at 160, 180, 200 and 220°C for 1, 2, 3 and 4h. The results show that heat treatment resulted in a darkened color, decreased moisture performance and increased dimensional stability of wood. Compared with untreated wood, equilibrium moisture content (EMC), water absorption (WA) and volume swelling (VS) for treated wood decrease up to 42.63%, 34.93% and 67.47%. The higher the treatment temperature and the longer the treatment time, the lower EMC, WA and VS. The VS of treated specimens has a more significant reduction than EMC and WA when the heat treatment temperature is above 180°C. The visual color changes were more distinct after heat treatment above 180°C. Temperature has a greater influence than time on these properties of specimens.

Effect of High Temperature on the Change in Color, Dimensional Stability and Mechanical Properties of Spruce Wood

Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 539-546 ◽  
Author(s):  
P. Bekhta ◽  
P. Niemz
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Dimensional Stability ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Treatment Time ◽  
Color Difference ◽  
Treatment Temperature ◽  
Color Changes

Summary In this study the effect of high temperature on mechanical properties, dimensional stability and color of spruce was investigated. Wood specimens conditioned at different relative humidities (50, 65, 80 and 95%) were subjected to heat treatment at 200°C for 2, 4, 8, 10 and 24 h and at 100, 150 and 200°C for 24 h. Color changes were measured in the Minolta Croma-Meter CR-300 color system. Bending strength and modulus of elasticity were determined according to DIN 52186. The results show that heat treatment mainly resulted in a darkening of wood tissues, improvement of the dimensional stability of wood and reduction of its mechanical properties. The darkening accelerated generally when treatment temperature exceeded approximately 200°C. Most of the darkening occurred within the first 4 h of exposure. For the specimens heated to high temperatures, the average decrease in bending strength was about 44–50%, while modulus of elasticity was reduced by only 4–9%. We found that treatment time and temperature were more important than relative humidity regarding the color responses. Strong correlations between total color difference and both modulus of elasticity and bending strength were found. Thus, the color parameters can be estimated quantitatively and used as a prediction of wood strength.

INFLUENCE OF THERMAL TREATMENT ON COLOUR PROPERTIES OF DRY POTATO PUREE

2018 ◽  
Author(s):  
И.М. ПОЧИЦКАЯ ◽  
Ю.Ф. РОСЛЯКОВ ◽  
В.В. ЛИТВЯК ◽  
Н.В. КОМАРОВА
Keyword(s):  
Color Change ◽  
Color Space ◽  
Color Difference ◽  
Treatment Temperature ◽  
Heating Process ◽  
Colour Properties ◽  
Color Changes ◽  
Organoleptic Characteristics ◽  
Before And After ◽  
Mashed Potatoes

Предложен способ оценки изменения цвета, основанный на обработке цифровых фотоизображений до и после температурно-временных воздействий. На основе полученных характеристик цветового пространства red–green–blue (RGB) был рассчитан показатель цветового различия ДE. Установлено, что с увеличением температуры термообработки образцов резко (на 50–80%) увеличивается значение цветовой разницы. При температуре 120°С значение цветовой разницы меняется незначительно и не превышает 15 единиц даже после 2-часового температурного воздействия. Однако при повышении температуры до 180–210°С цветовая разница за первые 10 мин увеличивается существенно и после 60 мин нагревания меняется незначительно. Проведенная оценка изменения цвета сухого картофельного пюре показала, что предлагаемый метод позволяет количественно оценить изменения цветовых характеристик продукта. Данная методика является чувствительной и более точной и дает возможность оценить не воспринимаемые человеком изменения цвета. Установлено следующее: контролируя температуру и длительность процесса нагревания, можно достичь желаемого цвета для сухого картофельного пюре, что напрямую влияет на его органолептические характеристики и потребительские свойства. A method for estimating the color change based on the processing of digital photo images before and after the temperature-time effects are proposed. Based on the received characteristics of the red–green–blue (RGB) color space, the color difference ДE was calculated. It is established that with increasing heat treatment temperature of the samples, the value of the color difference is sharply increased (by 50–80%). At a temperature of 120°C, the value of the color difference varies insignificantly and does not exceed 15 units even after a 2-hour exposure to temperature. However, with an increase in temperature 180–210°C, the color difference for the first 10 min increases substantially and after 60 minutes of heating changes insignificantly. The evaluation of the color change of dry mashed potatoes showed that the proposed method allows quantitative assessment of changes in color characteristics, is sensitive and more accurate, gives an opportunity to assess the color changes not perceived by a person. The received results demonstrate that controlling the temperature and duration of the heating process, it is possible to obtain the desired color of dry mashed potatoes, which is important, since color directly affects the organoleptic characteristics and consumer properties.

Effects of Heat Treatment Temperature on Photocatalytic Activity of TiO2/SiO2 Composite Aerogels

2013 ◽  
Vol 27 (10) ◽  
pp. 1079-1083
Author(s):  
Zhao-Hui LIU ◽  
Gen-Liang HOU ◽  
Xun-Jia SU ◽  
Feng GUO ◽  
Zhou XIAO ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Composite Aerogels

Spin-dependent-magnetoresistance control by regulation of heat treatment temperature for magnetite nano-particle sinter

2009 ◽  
Vol 18 (12) ◽  
pp. 935-938
Author(s):  
H. Kobori ◽  
T. Asahi ◽  
Y. Yamasaki ◽  
A. Sugimura ◽  
T. Taniguchi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Nano Particle

scholarly journals Water Resistance and Creep Behavior of Heat-Treated Moso Bamboo Determined by the Stepped Isostress Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Creep Behavior ◽  
Heat Treatment Temperature ◽  
Water Resistance ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Heat Treated

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

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